Application of supported Ni-Cu catalyst in alcohol amine alkylation reaction

Abstract

The application discloses application of a supported Ni-Cu catalyst in alcohol amine alkylation reaction, wherein the alcohol is a fatty alcohol, and the amine is an organic amine, and the alcohol amine alkylation reaction is carried out under the action of the supported Ni-Cu catalyst. The application can reduce the production cost of the catalyst, reduce the energy consumption of the alcohol amine alkylation reaction, and inhibit the side reaction caused by the breakage of C-N bonds in the raw material amine.

Description

Technical Field

[0001] This invention relates to the application of a Ni-Cu / Al2O3 catalyst in the alkylation reaction of alcoholamines. Background Technology

[0002] Amines are widely used in important fields such as chemical engineering, medical treatment, pharmaceuticals, and national defense. N,N-Diisopropylethylamine is an important organic synthesis intermediate, mainly used in the synthesis of pharmaceutical and pesticide intermediates, and can also be used as a solvent, condensing agent, and catalyst. Currently, there are several main synthesis processes for N,N-diisopropylethylamine. The most common production process uses diethyl sulfate and diisopropylamine as raw materials. This method is simple, but diethyl sulfate is highly toxic and expensive, resulting in high production costs. Large-scale use causes severe environmental pollution, and subsequent treatment with strong alkaline solutions generates large amounts of wastewater and waste salts, leading to high environmental costs. Another commonly used process uses ethane chloride and diisopropylamine as raw materials. This process has a high yield and is usually carried out in a batch reactor. It is simple to operate and can be quickly put into production with relatively low investment. However, the reactor has a long reaction cycle, limiting reaction time and yield. Because it is a batch reaction, the reactor's continuous production capacity is poor, making it unsuitable for large-scale production. Furthermore, the reactor has high energy consumption, requiring a large amount of energy to maintain the reaction temperature and pressure. The reaction is carried out under high pressure and with a large liquid holdup, posing significant safety risks. Acid-binding agents need to be added subsequently, which will generate a large amount of difficult-to-treat waste salt and a large amount of salt-containing solid waste. The subsequent separation process is complex and environmental protection costs are high.

[0003] Patent CN 106588672 A reports a method for synthesizing N,N-diisopropylethylamine from diisopropylamine and diethyl sulfate. This method is simple and is the most commonly used route. However, the raw material diethyl sulfate used in this method is highly toxic and causes serious environmental pollution.

[0004] Patent CN 111393301 A reports a method for synthesizing N,N-diisopropylethylamine from diisopropylamine and chloroethane. This reaction produces strong acid and requires high temperature, which can corrode equipment.

[0005] Patent CN 114105784 A reports a method for synthesizing N,N-diisopropylethylamine from diisopropylamine and ethanol. This method uses Mo-Ni-Cu / Al2O3 as a catalyst, and the product selectivity can reach up to 93.85% after distillation purification. However, the reaction is carried out at a high temperature of 180-230℃, which results in high energy consumption and high equipment requirements. In addition, a large number of byproducts are generated due to the breaking of the CN bond in diisopropylamine. Summary of the Invention

[0006] To address the problems existing in the prior art, the purpose of this invention is to provide an application of Ni-Cu / Al2O3 catalyst in the alkylation reaction of alcoholamines, so as to reduce the catalyst production cost, reduce the energy consumption of the alkylation reaction of alcoholamines, and suppress side reactions caused by the breaking of CN bonds in the raw material amine.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0008] Application of a supported Ni-Cu catalyst in the alkylation reaction of alcoholic amines, wherein the alcohol is a fatty alcohol and the amine is an organic amine, and the alkylation reaction is carried out under the action of the supported Ni-Cu catalyst. The preparation method of the supported Ni-Cu catalyst includes the following steps:

[0009] S1: Impregnation: according to n 镍 / n 铜 Nickel and copper salts are weighed and dissolved in a solvent at a molar ratio of 0.1-10 to obtain an impregnation solution. A metal oxide carrier is added to the impregnation solution, mixed evenly, and then thoroughly impregnated at an impregnation pressure of 0.05-0.1 MPa. The metal oxide carrier is alumina, zirconium oxide, or silicon oxide. The mass ratio of copper in the copper salt to the metal oxide carrier is 4.3-7.2:100.

[0010] S2: Rotary evaporation: The mixture of carrier and impregnation liquid obtained in S1 is rotary evaporated until the water is evaporated to obtain the rotary evaporation product;

[0011] S3: Calcination: Place the rotary evaporation product in a muffle furnace for calcination at a temperature of 350-500℃ for 3-4 hours. After calcination, cool the product to room temperature and remove it.

[0012] S4: Reduction: The calcined product is reduced at 500-700℃ under a hydrogen atmosphere. After 2-3 hours of reduction, the temperature is lowered to room temperature to obtain the supported Ni-Cu catalyst.

[0013] In step S1 of this invention, there are no special requirements for the selection of nickel salt and copper salt; they only need to be soluble in water. Preferably, in step S1, the nickel salt is one of nickel nitrate, nickel sulfate, nickel acetate, and nickel chloride, and the copper salt is one of copper nitrate, copper sulfate, and copper acetate, and the solvent is water.

[0014] Preferably, in step S1, the impregnation solution contains n 镍 / n 铜 =5-10, more preferably 6.

[0015] Preferably, in step S1, the immersion temperature is room temperature and the immersion time is 12-24 hours. More preferably, the immersion temperature is room temperature, the immersion pressure is atmospheric pressure (i.e., 0.1 MPa), and the immersion time is 20-24 hours.

[0016] Preferably, in step S2, the rotary evaporation pressure is 0-0.1 MPa, more preferably 0-0.05 MPa; the rotary evaporation temperature is 45-60℃, and the rotation speed is 90-130 rpm.

[0017] Preferably, in step S3, the calcination temperature is 400-500℃, more preferably 450℃. Preferably, in step S3, the calcination time is 4 hours. The present invention particularly prefers a calcination temperature of 450℃ and a calcination time of 4 hours.

[0018] Preferably, in step S4, the reduction temperature is 500-650℃, more preferably 650℃. Preferably, in step S4, the reduction time is 3 hours. The present invention particularly prefers a reduction temperature of 650℃ and a reduction time of 3 hours.

[0019] Preferably, the alcohol is one of ethanol, hexanol, and benzyl alcohol, and the amine is one of diisopropylamine, aniline, and N-methylaniline.

[0020] Preferably, the application is implemented as follows: an inert gas is introduced into a packed bed containing a supported Ni-Cu catalyst, the pressure inside the packed bed is adjusted to 0.2-0.4 MPa and the catalyst bed temperature is adjusted to 80-120°C, and a mixture of raw material alcohol and amine is introduced into the reactor for alkylation reaction.

[0021] As a further preferred option, the catalyst bed temperature is 80-100℃.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] (1) The present invention prepares a supported Ni-Cu catalyst with good dispersion, uniform particle size and high activity. Compared with the Mo-Ni-Cu / Al2O3 catalyst used in the prior art, on the one hand, the use of Mo metal is eliminated from the catalyst, reducing the catalyst cost; on the other hand, the catalyst can realize the activation and N-alkylation reaction of alcohols and amines at a lower temperature, reducing energy consumption; on the third hand, the catalyst can suppress the side reaction caused by the breaking of CN bond in the raw material amine, reducing the number of by-products.

[0024] (2) Compared with the existing diethyl sulfate and chloroethane processes, the present invention uses alcohols and amines as raw materials, which have low raw material costs and low production costs, thus reducing the cost of treating wastewater and waste salts.

[0025] (3) The present invention uses a packed bed for continuous production of N,N-diisopropylethylamine, which improves production safety and reduces labor costs compared with the original batch reactor. Moreover, the reaction is carried out under mild conditions of low temperature and low pressure, with low liquid holdup, high safety performance, and low equipment requirements. Detailed Implementation

[0026] The technical solution of the present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto:

[0027] Example 1:

[0028] Weigh 5g of 20-40 mesh alumina carrier, weigh a certain mass of nickel nitrate hexahydrate and copper nitrate trihydrate, dissolve them in water to form an impregnation solution (C). Ni(NO3)2·6H2O =1.2 mol / mL, C Cu(NO3)2·3H2O =0.2 mol / mL), the weighed alumina support was placed in 10 mL of impregnation solution and impregnated for 24 h at room temperature and atmospheric pressure. The resulting impregnation solution was dehydrated by rotary evaporation at 120 rpm under 95% vacuum and 55 °C to obtain dry alumina-supported nickel-copper solid, which was then calcined in a muffle furnace at 450 °C for 4 h to obtain the NiCu / Al2O3 catalyst. The obtained catalyst was packed into a reaction tube to form a packed bed, and in-situ reduction was carried out at 650 °C for 3 h under a hydrogen pressure of 0.1 MPa and a hydrogen flow rate of 40 mL / min. After purging with nitrogen and cooling to room temperature, the pressure was adjusted to 0.4 MPa through the back pressure valve. The temperature of the catalyst bed and vaporization chamber was adjusted to stabilize at 100 °C, and the liquid pump was started to pump the mixture of raw material ethanol and diisopropylamine (V 乙醇 V 二异丙胺 =1:1.25) with a volumetric hourly space velocity of 181.47 h⁻¹ -1 The reaction system was introduced and samples were taken after 9 hours of continuous reaction. GC analysis showed that the selectivity of the target product N,N-diisopropylethylamine was 91.29%. The selectivity of byproducts resulting from the breaking of the CN bond in diisopropylamine is shown in Table 1 below.

[0029] Table 1

[0030] substance Isopropanol Diethylamine N-Ethylisopropylamine Triethylamine Selectivity (%) 5.79 0.10 2.30 1.02

[0031] Example 2:

[0032] Weigh 5g of 20-40 mesh silica carrier, weigh a certain mass of nickel nitrate hexahydrate and copper nitrate trihydrate, dissolve them in water to form an impregnation solution (C). Ni(NO3)2·6H2O =1.2 mol / mL, C Cu(NO3)2·3H2O=0.2 mol / mL), the weighed silica support was placed in 10 mL of impregnation solution and impregnated for 24 h at room temperature and atmospheric pressure. The resulting impregnation solution was dehydrated by rotary evaporation at 120 rpm under 95% vacuum and 55 °C to obtain dry alumina-supported nickel-copper solid, which was then calcined in a muffle furnace at 450 °C for 4 h to obtain the NiCu / Al2O3 catalyst. The obtained catalyst was packed into a reaction tube to form a packed bed, and in situ reduced at 650 °C for 3 h under a hydrogen atmosphere, pressure of 0.1 MPa, and hydrogen flow rate of 40 mL / min. After purging with nitrogen and cooling to room temperature, the pressure was adjusted to 0.4 MPa through the back pressure valve. The temperature of the catalyst bed and vaporization chamber was adjusted to stabilize at 100 °C, and the liquid pump was started to pump the mixture of raw material ethanol and diisopropylamine (V 乙醇 V 二异丙胺 =1:1.25) with a volumetric hourly space velocity of 181.47 h⁻¹ -1 The reaction system was introduced and samples were taken after 9 hours of continuous reaction. The selectivity of the target product N,N-diisopropylethylamine was calculated to be 90.87% by GC analysis. The selectivity of byproducts generated by the breaking of the CN bond of diisopropylamine is shown in Table 2 below.

[0033] Table 2

[0034] substance Isopropanol Diethylamine N-Ethylisopropylamine Triethylamine Selectivity (%) 5.43 0.02 3.30 0.68

[0035] Example 3:

[0036] Weigh 5g of 20-40 mesh alumina carrier, weigh a certain mass of nickel nitrate hexahydrate and copper nitrate trihydrate, dissolve them in water to form an impregnation solution (C). Ni(NO3)2·6H2O =1.2 mol / mL, C Cu(NO3)2·3H2O =0.2 mol / mL), the weighed alumina support was placed in 10 mL of impregnation solution and impregnated for 24 h at room temperature and 95% vacuum. The resulting impregnation solution was dehydrated by rotary evaporation at 120 rpm under 95% vacuum and 55 °C to obtain dry alumina-supported nickel-copper solid, which was then calcined in a muffle furnace at 450 °C for 4 h to obtain the NiCu / Al2O3 catalyst. The obtained catalyst was packed into a reaction tube to form a packed bed, and in situ reduced at 650 °C for 3 h under a hydrogen atmosphere, pressure of 0.1 MPa, and hydrogen flow rate of 40 mL / min. After purging with nitrogen and cooling to room temperature, the pressure was adjusted to 0.4 MPa through the back pressure valve. The temperature of the catalyst bed and vaporization chamber was adjusted to stabilize at 100 °C, and the liquid pump was started to pump the mixture of raw material ethanol and diisopropylamine (V 乙醇 V 二异丙胺 =1:1.25) with a volumetric hourly space velocity of 181.47 h⁻¹ -1The reaction system was introduced and samples were taken after 9 hours of continuous reaction. The selectivity of the target product N,N-diisopropylethylamine was calculated to be 83.07% by GC analysis. The selectivity of byproducts caused by the breaking of the CN bond of diisopropylamine is shown in Table 3 below.

[0037] Table 3

[0038] substance Isopropanol Diethylamine N-Ethylisopropylamine Triethylamine Selectivity (%) 8.20 0.28 6.19 1.84

[0039] Example 4:

[0040] Weigh 10g of 20-40 mesh alumina carrier, weigh a certain mass of nickel nitrate hexahydrate and copper nitrate trihydrate, dissolve them in water to form an impregnation solution (C). Ni(NO3)2·6H2O =1.2 mol / mL, C Cu(NO3)2·3H2O =0.2 mol / mL), the weighed alumina support was placed in 10 mL of impregnation solution and impregnated for 24 h at room temperature and atmospheric pressure. The resulting impregnation solution was dehydrated by rotary evaporation at 120 rpm under 95% vacuum and 55 °C to obtain dry alumina-supported nickel-copper solid, which was then calcined in a muffle furnace at 450 °C for 4 h to obtain the NiCu / Al2O3 catalyst. The obtained catalyst was packed into a reaction tube to form a packed bed, and in-situ reduction was carried out at 650 °C for 3 h under a hydrogen pressure of 0.1 MPa and a hydrogen flow rate of 40 mL / min. After purging with nitrogen and cooling to room temperature, the pressure was adjusted to 0.4 MPa through the back pressure valve. The temperature of the catalyst bed and vaporization chamber was adjusted to stabilize at 100 °C, and the liquid pump was started to pump the mixture of raw material ethanol and diisopropylamine (V 乙醇 V 二异丙胺 =1:1.25) with a volumetric hourly space velocity of 181.47 h⁻¹ -1 The reaction system was introduced and samples were taken after 9 hours of continuous reaction. The selectivity of the target product N,N-diisopropylethylamine was calculated to be 86.40% by GC analysis. The selectivity of byproducts caused by the breaking of the CN bond of diisopropylamine is shown in Table 4 below.

[0041] Table 4

[0042] substance Isopropanol Diethylamine N-Ethylisopropylamine Triethylamine Selectivity (%) 6.68 0.17 5.67 1.07

[0043] Example 5:

[0044] Weigh 5g of 20-40 mesh alumina carrier, weigh a certain mass of nickel nitrate hexahydrate and copper nitrate trihydrate, dissolve them in water to form an impregnation solution (C). Ni(NO3)2·6H2O =1.2 mol / mL, C Cu(NO3)2·3H2O=0.2 mol / mL), the weighed alumina support was placed in 10 mL of impregnation solution and impregnated for 24 h at room temperature and atmospheric pressure. The resulting impregnation solution was dehydrated by rotary evaporation at 120 rpm under 95% vacuum and 55 °C to obtain dry alumina-supported nickel-copper solid, which was then calcined in a muffle furnace at 400 °C for 4 h to obtain the NiCu / Al2O3 catalyst. The obtained catalyst was packed into a reaction tube to form a packed bed and reduced in situ at 650 °C for 3 h under a hydrogen pressure of 0.1 MPa and a hydrogen flow rate of 40 mL / min. After purging with nitrogen and cooling to room temperature, the pressure was adjusted to 0.4 MPa through the back pressure valve. The temperature of the catalyst bed and vaporization chamber was adjusted to stabilize at 100 °C, and the liquid pump was started to pump the mixture of raw material ethanol and diisopropylamine (V 乙醇 V 二异丙胺 =1:1.25) with a volumetric hourly space velocity of 181.47 h⁻¹ -1 The reaction system was introduced and samples were taken after 9 hours of continuous reaction. The selectivity of the target product N,N-diisopropylethylamine was calculated to be 77.18% by GC analysis. The selectivity of byproducts generated by the breaking of the CN bond of diisopropylamine is shown in Table 5 below.

[0045] Table 5

[0046] substance Isopropanol Diethylamine N-Ethylisopropylamine Triethylamine Selectivity (%) 6.84 0.17 13.41 2.40

[0047] Example 6:

[0048] Weigh 5g of 20-40 mesh alumina carrier, weigh a certain mass of nickel nitrate hexahydrate and copper nitrate trihydrate, dissolve them in water to form an impregnation solution (C). Ni(NO3)2·6H2O =1.2 mol / mL, C Cu(NO3)2·3H2O =0.2 mol / mL), the weighed alumina support was placed in 10 mL of impregnation solution and impregnated for 24 h at room temperature and atmospheric pressure. The resulting impregnation solution was dehydrated by rotary evaporation at 120 rpm under 95% vacuum and 55 °C to obtain dry alumina-supported nickel-copper solid, which was then calcined in a muffle furnace at 450 °C for 4 h to obtain the NiCu / Al2O3 catalyst. The obtained catalyst was packed into a reaction tube to form a packed bed, and in-situ reduction was carried out at 500 °C for 3 h under a hydrogen pressure of 0.1 MPa and a hydrogen flow rate of 40 mL / min. After purging with nitrogen and cooling to room temperature, the pressure was adjusted to 0.4 MPa through the back pressure valve. The temperature of the catalyst bed and vaporization chamber was adjusted to stabilize at 100 °C, and the liquid pump was started to pump the mixture of raw material ethanol and diisopropylamine (V 乙醇 V 二异丙胺 =1:1.25) with a volumetric hourly space velocity of 181.47 h⁻¹ -1The reaction system was introduced and samples were taken after 9 hours of continuous reaction. GC analysis showed that the selectivity of the target product N,N-diisopropylethylamine was 70.77%. The selectivity of byproducts resulting from the breaking of the CN bond in diisopropylamine is shown in Table 6 below.

[0049] Table 6

[0050] substance Isopropanol Diethylamine N-Ethylisopropylamine Triethylamine Selectivity (%) 15.59 0.11 5.41 8.12

[0051] Example 7:

[0052] Weigh 5g of 20-40 mesh alumina carrier, weigh a certain mass of nickel nitrate hexahydrate and copper nitrate trihydrate, dissolve them in water to form an impregnation solution (C). Ni(NO3)2·6H2O =1.2 mol / mL, C Cu(NO3)2·3H2O =0.2 mol / mL), the weighed alumina support was placed in 10 mL of impregnation solution and impregnated for 24 h at room temperature and atmospheric pressure. The resulting impregnation solution was dehydrated by rotary evaporation at 120 rpm under 95% vacuum and 55 °C to obtain dry alumina-supported nickel-copper solid, which was then calcined in a muffle furnace at 500 °C for 4 h to obtain the NiCu / Al2O3 catalyst. The obtained catalyst was packed into a reaction tube to form a packed bed, and in-situ reduction was carried out at 500 °C for 3 h under a hydrogen pressure of 0.1 MPa and a hydrogen flow rate of 40 mL / min. After purging with nitrogen and cooling to room temperature, the pressure was adjusted to 0.4 MPa through the back pressure valve. The temperature of the catalyst bed and vaporization chamber was adjusted to stabilize at 100 °C, and the liquid pump was started to pump the mixture of raw material ethanol and diisopropylamine (V 乙醇 V 二异丙胺 =1:1.25) with a volumetric hourly space velocity of 181.47 h⁻¹ -1 The reaction system was introduced and samples were taken after 9 hours of continuous reaction. The selectivity of the target product N,N-diisopropylethylamine was calculated to be 78.22% by GC analysis. The selectivity of byproducts generated by the breaking of the CN bond of diisopropylamine is shown in Table 7 below.

[0053] Table 7

[0054] substance Isopropanol Diethylamine N-Ethylisopropylamine Triethylamine Selectivity (%) 10.53 0.09 10.15 1.01

Claims

1. The application of a supported Ni-Cu catalyst in the alkylation reaction of alcoholamines, wherein the alcohol is ethanol and the amine is diisopropylamine, characterized in that: The application is specifically implemented as follows: an inert gas is introduced into a packed bed containing a supported Ni-Cu catalyst, the pressure inside the packed bed is adjusted to 0.2-0.4 MPa and the catalyst bed temperature is adjusted to 80-120℃, and a mixture of raw material alcohol and amine is introduced into the reactor for alkylation reaction; The alkylation reaction of the alcoholamine is carried out in the presence of a supported Ni-Cu catalyst, and the preparation method of the supported Ni-Cu catalyst includes the following steps: S1: Impregnation: according to n 镍 / n 铜 Nickel and copper salts were weighed in a solvent at a molar ratio of 6 to obtain an impregnation solution. A metal oxide carrier was added to the impregnation solution, mixed thoroughly, and then fully impregnated. The impregnation temperature was room temperature, the impregnation pressure was atmospheric pressure, and the impregnation time was 20-24 hours. The metal oxide carrier was alumina, zirconium oxide, or silicon oxide. The mass ratio of copper in the copper salt to the metal oxide carrier was 4.3-7.2:

100. S2: Rotary evaporation: The mixture of carrier and impregnation liquid obtained in S1 is rotary evaporated until the water is evaporated to obtain the rotary evaporation product; S3: Calcination: Place the rotary evaporation product in a muffle furnace for calcination at a temperature of 450℃ for 3-4 hours. After calcination, cool the product to room temperature and remove it. S4: Reduction: The calcined product was reduced at 650°C under a hydrogen atmosphere. After 2-3 hours of reduction, the temperature was lowered to room temperature to obtain the supported Ni-Cu catalyst.

2. The application as described in claim 1, characterized in that: In step S3, the roasting time is 4 hours.

3. The application as described in claim 1, characterized in that: In step S4, the restoration time is 3 hours.

4. The application as described in claim 1, characterized in that: The catalyst bed temperature is 80-100℃.